In DLNA (Digital Living Network Alliance), a guideline for guaranteeing the mutual compatibility among electric appliances, PCs, and mobile equipment is prescribed. When equipment units conforming to the guideline are connected to a home network, they are mutually connected to share digital contents such as music, photographs, moving pictures, and the like. It is predicted that the equipment units conforming to the DLNA are used not only over a home network but also over an onboard network in the future. The network that has an equipment unit conforming to the DLNA connected thereto will be referred to as “a DLNA network” below.
On the other hand, the HDD portable player is carried by a user with a great number of music pieces held on the HDD (hard disk device) so that the music pieces can be played. As a usage aspect of the HDD portable player, a user connects his or her HDD portable player to his or her home or automobile DLNA network through a wireless LAN or a cable LAN and plays a music piece held in the HDD portable player with a network player to listen to the music alone or as a group of his or her family members or friends.
Japanese Patent Application Laid-Open No. 2004-208204 (Patent Document) discloses a hard disk recorder for recording television programs that automatically deletes contents corresponding to a predetermined condition from contents stored therein when the hard disk, although with a large capacity, has stored many amounts of contents data so that an insufficient capacity is left for storing a new television program.